Working Papers

The welfare associated with public insurance is often difficult to quantify. Relative to private insurance, a fundamental difficulty is that public insurance is typically compulsory, so the demand for coverage is unobserved and thus cannot be used to analyze welfare. However, in many public insurance settings, individuals can purchase private insurance to supplement their public coverage. In this paper, we outline an approach to use data and variation from private complementary insurance to quantify welfare associated with several counterfactuals related to compulsory public insurance. Using administrative data from one large firm on employee long-term disability insurance, we then apply this approach empirically to quantify the value of disability insurance among this population. We use p...

A central question in the debate over privatized Medicare is whether increased government payments to private Medicare Advantage (MA) plans generate lower premiums for consumers or higher profits for producers. Using difference-in-differences variation brought about by a sharp legislative change, we find that MA insurers pass through 45% of increased payments in lower premiums and an additional 9% in more generous benefits. We show that advantageous selection into MA cannot explain this incomplete pass-through. Instead, our evidence suggests that market power is important, with premium pass-through rates of 13% in the least competitive markets and 74% in the most competitive.

Most health insurance uses cost-sharing to reduce excess utilization. Supplemental insurance can blunt the impact of this cost-sharing, increasing utilization and exerting a negative externality on the primary insurer. This paper estimates the effect of private Medigap supplemental insurance on public Medicare spending using Medigap premium discontinuities in local medical markets that span state boundaries. Using administrative data on the universe of Medicare beneficiaries, we estimate that Medigap increases an individual’s Medicare spending by 22.2%. We calculate that a 15% tax on Medigap premiums generates savings of $12.9 billion annually. A Pigouvian tax generates annual savings of $31.6 billion.

Because of the obtrusive manner in which they are normally paid, property taxes are likely the most salient taxes in the U.S. However, they are much less salient to homeowners with tax escrow. Exploiting geographical variation in tax escrow, we test how salience affects property tax rates and limits. We instrument for tax escrow using bank holding companies' national mortgage servicing assets, focusing on companies that have local branches but do most of their business outside the area. We find that a one standard deviation increase in tax escrow produces about a one standard deviation decrease in property tax rates.